Agra Red Fort a UNESCO World Heritage site located in Agra, India. It is about 2.5 km northwest of its more famous sister monument, the Taj Mahal. Complex was built as the palace fort of Shahjahanabad – the new capital of the fifth Mughal Emperor of India, Shah Jahan. The Red Fort has walls extending up to 2 km in length with the height varying from 18 m on the river side to 33 m on the city side. The Red Fort Delhi has two main entrances, the Delhi Gate and the Lahori Gate. The fort was built by Ustad Ahmad Lahori, who had worked with the architect of the Taj Mahal. The fort takes its name from the massive wall of red sandstone that defines its eight sides. The Red Fort Complex took almost a decade to complete and covers a staggering 120 acres, at one time holding a population of 3,000 people. The Red Fort Complex consists of numerous impressive structures, including the Diwan-i-Am or Hall of Public Audience, once the home of the royal throne and the private apartments along the Stream of Paradise or Nahr-i-Behisht as well as several other palaces and even the Chhatta Chowk or palace market.